This invention relates to a method of preventing the escape of liquid nitrogen and nitrogen gas from an apparatus for treating materials with high energy ionizing radiation while the materials are being maintained at temperatures below about -40.degree. C. with liquid nitrogen.
Conventional packing materials used to seal certain joints in pipelines conducting liquid nitrogen into an apparatus in which materials have been exposed to high energy ionizing radiation at low temperatures, such as below -40.degree. C., have deteriorated very rapidly under the combination effects of high energy ionizing radiation and low temperatures. Such packings have required frequent replacement, thus increasing labor as well as material costs.
It is an object of the present invention to provide a method of preventing the escape of liquid nitrogen and nitrogen gas from an apparatus for treating materials with high energy ionizing radiaton while the materials are being maintained at temperatures below about -40.degree. C. with liquid nitrogen.
It is another object of the invention to provide packing for connectible and disconnectible joints in conduits for liquid nitrogen being used to maintain a low temperature within an apparatus in which materials are exposed to high energy ionizing radiation while being maintained at the low temperature.
Other objects and advantages will become apparent from the following description of the invention.